Electrical connector



June 5, 1956 Filed July 2, 1952 S. S. PIGMAN ETAL ELECTRICAL CONNECTOR 2 Sheets-Sheet l BY I June 1956 s. s. PIGMAN ET AL 2,749,383

ELECTRICAL CONNECTOR 2 Sheets-Sheet 2 Filed July 2, 1952 ELECTRICAL CONNECTOR Samuel S. Pigman and George J. Thompson, New York, N. Y.

Application July 2, 1952, Serial No. 296,978

8 Claims. (Cl. 174-84) (Granted under Title 35, U. S. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to connectors and more particularly pre-insulated solderless electrical connectors adaptable for use on insulated, partially insulated, or noninsulated electric wires.

More particularly, this invention relates to electric wire connectors for firmly joining the ends of a plurality of wires wherein the conductors proper in the ends to be joined are of the same size and are usually formed of a plurality of strands of copper twisted together and surrounded by insulation.

In setting up an electrical circuit numerous connections are made. Generally speed in the order of seconds for making a connection is unnecessary. Of greater importance is permanence and reliability. A multiplicity of connectors are presently available to fill the many general and specific needs that arise in setting up a circuit. However following an explosion or like catastrophe in an installation having electrical wiring it is frequently necessary to repair the damage to the electric circuits immediately to preclude further damage or injury in the installation and elsewhere. Aboard ship particularly it is often vital to repair circuits immediately following shipboard damage. In addition to the need for haste there is often lack of space in which to carry out repairs and a need for a small splice. Furthermore any connection made should provide wherever possible a reliable electrical continuity, a stable millivolt drop that equals that of an equal legth of the wire being spliced and good mechanical pull out strength. To meet as closely as possible all the requirements an electrical connector according to this invention is adapted for application to ends of wires just as they are by the crimping action of a single portable tool.

An object of this invention is to provide an improved connecting means.

A further object is to provide an improved pro-insulated solderless electrical connector.

A further object is to provide a pre-insulated solderless connector that may be put in use in a fraction of a minute.

A further object of this invention is to provide a preinsulated solderless connector that may be manually installed with a suitable tool in a small fraction of a minute and has a high pullout strength, low inillivolt drop, and high dielectric strength between the joined wires and the outside of the connector housing.

A further object is to provide an electrical connector which can be quickly applied Without removal or stripping of the insulation covering of the connected portions of insulated wires.

A further object is to provide an electrical connector which .is crimped to make connection and which crimp does not recover sufficiently when the crimping force is nited States Patent ice removed whereby the contact resistance is not increased appreciably.

A further object is to provide a versatile type of connecting device for use on either insulated, partially insulated or bare metallic wires of either the solid or stranded type.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. l is an isometric view broken away in parts showing the connector ready for use,

Fig. 2 is a cutaway isometric view of the connector according to Fig. 1 after being crimped into positive engagement with a pair of wire conductors,

Fig. 3 is an isometric view of the conducting bridge that is part of the connector illustrated in Figs. 1 and 2, and

Fig. 4 is a fractional side view of a tool for use in crimping the connector and including, in phantom, a conne'ctor shown in position.

A preferred embodiment of this invention, illustrated in Fig. l, is contained in a sheet metal housing it). The housing 10 is substantially cube-shaped. A pair of opposite end walls 11, 12 of the housing 10 have openings 13 and 14 cut out of a corner of each end wall. Both openings are adjacent the side 15 of the housing 10 but out of alignment with one another for reasons which are set forth further in this description. Housing side 16 which is opposite side 15 is slotted at two places 17 and 18 thereby dividing the side 16 into three sections. The slots extend part way down each of the sides adjacent the side 16.

The housing ll) is provided With a separate liner 19 made of a. flexible, tough, insulating material of high dielectric strength which covers the housings entire inside surface. One example of a suitable material is fish paper. By employing the insulator 19, the connector may be freely handled and may be left resting in any position after it is in place in the circuit without any need for additional insulating covering.

A bridging bar 20 is included in the housing 10, the bridging bar being more clearly shown in Fig. 3. The bar 29 is made of a material combining very high conductivity and toughness. Ideally, the overall conductivity of the connector should equal the conductivity of the wires spliced. Since the contact resistance of the connector decreases the overall conductivity of the connector it is desirable to produce the bridging bar 20 of a material that has a higher conductivity than the spliced wire. In addition the teeth 21 of the bridging bar 20 must be capable of cutting through various kinds of wire insulation in general use to make good contact with the wires. In practice the bridging bar 20 may be made of a high copper alloy plated with silver which combines good conductivity with high strength or toughness.

To maintain the bridging bar in proper position for ready use the bar may be glued to the insulating liner in the position shown in Fig. 1.

To further increase the insulating property of the conneetor the inner and outer surface of housing 10 is painted with a varnish.

The connector is secured to Wire ends that are inserted therein by deforming the center section 22 of the side 16 into a V shape thereby forcing the bridging bar 20 into good contact with the wires. Early attempts to produce a connection having stable low contact resistance by crimping were unsatisfactory due to the partial recovery from deformation of the crimped side of the housing or shell. Through partial recovery the pressure on the contact is relieved when the external crimping force is removed thereby increasing the contact resistance. This lack of stability of the deformed section is overcome by slotting one side as at 17, 18 to produce three sections and then deforming the central section 22 independently of the remainder of the housing as clearly shown in Fig. 2. Through the use of the slotted arrangement only a minimum of recovery follows crimping. The indented section 22 forms a V and the two undeformed adjacent sections form ties across the top of the V. Thus a rigid static structure is formed which minimizes release of the contact pressure to a measurable degree.

la use the connector receives the wire ends to be spliced without any preparation of the said wire ends. All splices are made without removing any insulation and braid. The wire ends are inserted through the openings 13 l4 far enough to abut the walls of the housing opposite the openi; By positioning the wire ends along the entire length of the housing each wire end is gripped by both rows of teeth 21 insuring good electrical contact while increasing the mechanical strength of the splice. After the wires are in place the center section 22 is crimped by using a tool 23 shown by phantom lines in Fig. I. As the crimping force is applied by the tool 23 the teeth of the bridging bar cut through the insulation, it any, on the wires being spliced and then make contact with the wires, firmly gripping the said wires. No insulation is needed because the insulating liner 19 and the covering of varnish added to the connector is ample to thoroughly insulate the connector.

By using the connector according to this invention time consumed in making a splice has been as little as 10 seconds.

The shape of the parts and the location of the openings may be readily modified with deviating from the scope of the invention.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. it is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

We claim:

1. An electrical connector comprising a substantially cubic sheet metal housing having a pair of end walls, each of said end walls formed with an opening dimensioned to permit entry of a preselected range of sizes of unbared conductors, the openings being formed adjacent one side of the housing but out of alignment with each other, the side of said housing opposite said one side being formed with two adjacent elongated through slots between tie end walls dividing the said opposite side into three sections, the slots extending the entire width of the said opposite side and partially into each of the sides adjacent said opposite side, a flexible, tough, insulating liner provided within said housing, an electrically conductive bridging member fastened to a portion of the liner adjncent the said opposite side whereby it is positioned for immediate use, said bridging member having a row of teeth at each of its two ends, the teeth being constructed and arranged to cut through insulation of conductors to s iiced by the connector, whereby an unbared conductor may be inserted through each opening to the op- POsit'e end of the housing and the center section of the slotted side deformed inwardly in a V shape to force said bridging member into engagement with the wire conductors to provide a good electrical connection and a strong splice, said V-shaped deformation bordered by two cross straps thereby having a minimum tendency to recover.

2. An electrical connector comprising a metal housing formed as a cylindrical shell with an opening through each of its ends and with two adjacent transverse coextensive slots extending part way around said housing intermediate the ends thereof, the portion of said housing included between the slots being continuous and integral at its ends with the remainder of said housing, an electrically conductive bridging bar formed with a portion on one side thereof for biting into conductors, said bridging bar being positioned in said housing with its side opposite to its one side disposed contiguous with the portion of said housing between the slots whereby when a pair of wire conductors is in said housing, the portion of said housing between the slots may be deformed inwardly into V-s'nape to force said bridging bar into biting contact with the wire conductors.

3. An electrical connector comprising a metal hous ing formed 5 a cylindrical shell with an opening through each of its ends and with two adjacent transverse coextensive slots extending part way around said housing intermediate the ends thereof, the ends of the portion of sad housing included between the slots being integral i the remainder of said housing, an elecally conductive bridging bar formed with teeth on one with the side thereof opposite its toothed side adjacent the portion of said housing between the slots whereby when a pair of wire conductors is in said housing between the toothed side of said bridging bar and said housing the portion of said housing between the slots may be deformed inwardly into V-shape to force said bridging bar into contact with the wire conductors.

4. An electrical connector comprising a metal housing formed as a cylindrical shell with an opening through each of its ends ard with two adjacent transverse coextensive slots extending part way around said housing intermediate the ends thereof, the ends of the portion of said housing included between the slots being integral at its ends with the remainder of said housing, an in sulating liner covering the inside surface area of said housing, an electrically conductive bridging bar formed with teeth on one side thereof, said bridging bar positioned in said housing with the side thereof opposite its toothed side adjacent the portion of said liner between the slots, whereby when a pair of wire conductors is in said housing between the toothed side of said bridging bar and the portion of said liner opposite the slotted portion, the portion of said housing and said liner between the slots may be deformed inwardly into V-shape to force said bridging bar into contact with the wire conductors.

5. An electrical connector comprising a metal housing formed as a cylindrical shell with closed ends, a preselected size opening formed in each of the ends of said housing in such positions that if both openings and the inner surface of said housing are projected onto a cominon transverse plane the projections of the openings are adjacent but do not overlap, and are bounded by a portion of the projection of the inner surface of said housing, said housing being formed with two adjacent transverse coextensive slots extending part way around said housing intermediate the ends thereof and opposite that portion of the inner surface of the housing whose projection bounds the end openings, the portion of said housing included between the slots being continuous and integral at its ends with the remainder of said housing, an electrically conductive bridging bar formed with a portion on one side thereof for biting into conductors, said bridging bar being positioned in said housing with its side opposite to its one side disposed contiguous with the portion of said housing between the slots whereby the ends of wire conductors may be inserted through the openings in the ends of said housing to abut the opposite ends of said housing and the portion of said housing between the slots may be deformed inwardly into V-shape to force said bridging bar into biting contact with the wire conductors.

6. An electrical connector comprising a metal housing formed as a cylindrical shell with closed ends, a preselected size opening formed in each of the ends of said housing in such positions that if both openings and the inner surface of said housing are projected onto a common transverse plane the projections of the openings are adjacent but do not overlap, and are bounded by a portion of the projection of the inner surface of said housing, said housing being formed with two adjacent transverse coextensive slots extending part way around said housing intermediate the ends thereof and opposite that portion of the inner surface of said housing whose projection bounds the end openings, the portion of said housing included between the slots being continuous and integral at its ends with the remainder of said housing, an insulating liner covering the inside surface area of said housing, an electrically conductive bridging bar formed with a portion on one side thereof for biting into conductors, said bridging bar being positioned in said housing with its side opposite to its one side disposed contiguous with the portion of said liner between the slots whereby the ends of wire conductors may be inserted through the openings in the ends of said housing to abut the opposite ends of said housing and the portion of said housing between the slots may be deformed inwardly into biting V-shape to force said bridging bar into contact with the wire conductors.

7. An electrical connector comprising a metal housing formed as a cylindrical shell with closed ends, a preselected size opening formed in each of the ends of said housing in such positions that if both openings and the inner surface of said housing are projected onto a common transverse plane the projections of the openings are adjacent but do not overlap and are bounded by a portion of the projection of the inner surface of said housing, said housing being formed with two adjacent transverse coextensive slots extending part way around said housing intermediate the ends thereof and opposite that portion of the inner surface of said housing whose surface bounds the end openings if projected onto a common transverse plane, the ends of the portion of said housing included between the slots being integral at its ends with the remainder of said housing, an insulating liner covering the inside surface area of said housing, an electrically conductive bridging bar formed with teeth on one side thereof, said bridging bar positioned in said housing with the side thereof opposite its toothed side glued to said liner adjacent the slots whereby the ends of unbared wire conductors may be inserted through the openings in the ends of said housing to abut the opposite ends of said housing and the portion or" said housing between the slots may be deformed inwardly into V-shape to force said bridging bar into contact with the wire conductors. 8. An electrical connector comprising a metal housing formed as a rectangular cylindrical shell with closed ends, a preselected size opening formed in each of the ends of said housing in such positions that if both openlugs and the inner surface of said housing are projected onto a common transverse plane the projections of the openings are adjacent but do not overlap and are bounded by one side of the projection of the inner surface of said housing, said housing being formed with two adjacent transverse coextensive slots through the side opposite the side whose projection bounds the projections of the openings, the slots extending into the adjacent sides of said housing, the ends of the portion of said housing included between the slots being integral at its ends with the remainder of said housing, an insulating liner covering the inside surface area of said housing, an electrically conductive bridging bar formed with teeth on one side thereof, said bridging bar positioned in said housing with the side thereof opposite its toothed side glued to said liner adjacent the slots whereby the ends of unbared wire conductors may be inserted through the openings in the ends of said housing to abut the opposite ends of said housing and the portion of said housing between the slots may be deformed inwardly into V-shape to force said bridging bar into contact with the wire conductors.

References Cited in the file of this patent UNITED STATES PATENTS 1,488,636 Geiser Apr. 1, 1924 2,316,267 McLarn Apr. 13, 1943 2,324,829 Dante July 20, 1943 2,355,387 Main Aug. 8, 1944 2,389,255 Graham Nov. 20, 1945 2,525,123 Frank Oct. 10, 1950 2,587,239 Smith Feb. 26, 1952 FOREIGN PATENTS 223,624 Switzerland Dec. 16, 1942 

